There are several different dragons in My Little Pony: Friendship Is Magic. I was wondering if they have already been classified or if there is a name for their types? Specifically, I want to know the name of the type of Spike the dragon and the dragons from the episodes "Dragonshy","Owls Well That Ends Well", and "Dragon Quest". I know they are mostly different types, but I want to know their type names.
S2 E21 “Dragon Quest” has Twilight claiming “ponies know next to nothing about dragons”, and the series mostly depicts Equestria from the ponies' point of view, so we know next to nothing about dragons in general too.
That said, I believe we have seen only one type of dragon in the episodes so far: fire dragons. I don't recall any dragon being described to be any other type.
In S1 E5 “Griffon the Brush Off”, Spike claims “dragons are fireproof”, which may indicate that all the dragons in the ponyverse are fire-breathing dragons. Spike, however, isn't really an authority on this, because he hasn't met other dragons yet (see S2 E21). In Equestria Girls, Spike claims he is “a ferocious, fire-breathing dragon” in the ponyverse. In S4 E24, Mrs. Harshwhinny calls Spike “a fire-breathing dragon“.
In S1 E07 “Dragonshy”, the dragon was definitely a fire-breathing kind (Fluttershy explicitly says it breathes fire). The dragon in S1 E24 breathes something that appears to be fire.
In S2 E21, Fluttershy assumes the migrating dragons are “Big, scaly, fire-breathing dragons” before having seen them – but in context, this statement might not have meant to characterize all the dragons, it could apply to only some of them. The teenage dragons Spike meets in that episode all jump into lava, which shows they are completely fireproof just like Spike, so they are probably fire dragons as well.